The Key That Connects All
by FantasyCrest
Summary: As the Master of Masters waits for various stories to play out he decides to head a a few universes over where he discovers one Midoriya Izuku and decides to give him a Keyblade and a new story evolves from there. Disclaimer inside.
1. Prologue

The Key That Connects All

Prologue

 _After I vanished from the world I knew it would take time for Luxu to fulfill his role. Time for Ira, Ava, and the others to play their parts. So, I would need to find a way to occupy myself luckily, I know how to access the multiverse. So away from the Realm of Light I go and there's one universe in particular I find my sight has stumbled upon. On a world called Earth humans began to develop powers and abilities of all kinds and they began to call them Quirks. Those Quirks took a variety of forms from physical transformations to using the elements as play toys. It also led to a time of chaos which in turn gave way to the rise of a superpowers society with heroes and villains. Such an interesting place! And more importantly there's someone I've noticed who happens to show a lot of potential…_

 **Mustufau, Japan**

In the streets of this city a boy with freckles walks down by himself. He has dark hair with a green tint that grows rather wild. His eyes are bright green as well and right now he… is rather beaten up.

You see this little boy is named Midoriya Izuku, currently 8 years old and he is Quirkless. He was on his way home from the park after his former friend Bakugou Katsuki and his lackeys proceeded to beat him up, again.

 _The world's so unfair_ Izuku thinks to himself for what must over the 100 hundredth time by now.

"Hey there kiddo!" A voice called out in front of him stopping him dead. Looking up Izuku saw a figure in a black coat with the hood obscuring his face with black leather pants and boots under it.

The man waved. Izuku immediately did a 180 and tried to run key word being tried, he was kinda too beat up to get away.

"Woah, woah there easy I'm not gonna hurt you!"

The man was suddenly in front of him and Izuku was ready to scream or something but before he could the man said "here" and placed a hand on his shoulder and a light enveloped him for a second and when it faded Izuku felt much better.

He blinked and looked down at himself and found that his bruises and scrapes were gone and the dirt that had adorned his form were gone. Looking up he found the man peering down at him "feeling better?" He asked.

Izuku nodded and said "yes, um thank you."

The man nodded. "Good I've been looking forward to meeting you."

Izuku blinked "why?"

The man looked at him and said "would you like a Quirk?"

Izuku felt his heart jolt and he tried hard not to shout "yes!"

And the response "Well I can't give you one" had him fighting not to face plant into the cement. "But I **can** give you something that can function like one maybe even better depending on how you use it."

Izuku looked up at him trying his hardest not to hope but failing while at the same time also wondering if he should try and run for it. Mysterious stranger just appearing like this and offering his dreams on a plate is definitely something his Mom would want him avoiding and yet… hope made him stay.

The man raised his right hand and placed it about level and in front hos his left shoulder then he waved it moving it from in front his left shoulder to his right. Green light then gathered into his palm before surging left in a manner not akin to lightning with a fwish sound that had him taking a step backward in fright slightly but it quickly faded and what was left behind had him… curious.

The object the mysterious man held, Izuku couldn't decide if it was supposed to be a key or a sword. The whole thing was a solid green color for the most part. A basic oval formed a guard with a handle in the center. Set into the guard was a blue gem shaped like an eye. The shaft above the guard was nearly the length of a baton and jutting just before the end was a flat star that on the inside had a silhouette of a shape that vaguely reminded Izuku of rabbit ears. Rounding it all out on the bottom of the guards with a circle attached to it was a keychain of sorts the end which had a simple charm that with another eye gem set into it.

The man lightly made a tossing motion so that he was holding the object by the shaft just above the guard then he knelt down and offered the handle to Izuku.

The young boy looked at the stranger and then back at the strange object. He wanted the possibility this stranger was offering so bad. But at the same time, he didn't want to be disappointed and more importantly the man was a stranger. But he did also heal him so he couldn't be that bad right? His thoughts ran like this for a good minute before the man said "here take it."

Izuku looked at the stranger's face but couldn't see anything in the shadows of the hood then at the strange object then raising one hand out he began to reach for it, halted, and then completed the gesture little fingers curling around the handle. The stranger let go and Izuku now held the mysterious object by himself with just a bit of strain not used to the weight.

And just like that in the Master of Masters playful and mischievous way he set in motion a new story, a story that had the potential to be rather intriguing and could go a lot of ways!

* * *

 **Author's Note: Ladies and gents here is my newest project a BNHA fic (and KH crossover sort of). I won't lie I'm a little nervous posting this and as it will be my first piece that's M/M but here we go. The whole premise behind this started with me wondering "hey what if the Master of Masters gave Deku a Keyblade and proceeds to mess with his life in various ways because why not" then I talked to my friend Tolby and the thing evolved so here we are. Now this fic won't have Sora and company taking part nor will there be the usual cast of enemies taking part (except Nightmares I'm on the fence with them still) we'll be using a lot of Kingdom Hearts themes and terms but except for the Master of Masters and a Chirithy that's all there will be for now. The pairing for this fic will be Tokoyami/Midoriya but it'll take me a bit to get there. The cover attached is something I made and there's a drawing you can see on the other sites I use. Not much else to say. Thanks goes to Tolby whose agreed to be my beta reader for this project. I don't own Boku No Hero Academia or the Kingdom Hearts series in any way, shape, or form. Tell me what you think!**


	2. Chapter 01

The Key That Connects All

Chapter 01

What Can Be Done

The door of the Midoriya's apartment unlocked and opened and in walked Izuku. A rather panicky look was on his face as he took off his shoes and walked inside.

The little boy had no idea what to do, or even how to explain how this to his mom.

 _Oh God Mom!_ Izuku suddenly thinks or maybe shrieks in his mind as a voice conveniently calls from the kitchen.

"Izuku honey is that you?"

Izuku wondered _how the heck this was gonna go?_

It went rather OK contrary to what he was thinking as his mom clearly noticed how panicky he was but decided not to press him **yet** as Izuku was able to escape to his room easily enough and once alone he decided that maybe some practice was in order.

 _But how do I do this?_ Izuku wonders. It's not like the Stranger in the Black Coat had given him instructions on how to use… whatever it was he gave him. The mysterious figure sort of just faded away like a ghost and the thing he had given him had vanished in the same light that the figure had summoned it!

Remembering the way the figure had summoned it he held his right hand in front of his left shoulder and moved it horizontally and thought to himself _come here…_

And as he closed his hand green light gathered in his hand and Izuku felt equal parts thrill and worry go through him as it whooshed outward and he felt weight in his hand that pulled his arm down as it settled in his hand.

Izuku hefted the object slightly the weight being something rather substantial. He could hold it one handed but using it two handed made holding seem a bit easier. Calling up memories of glimpses of kendo matches, video games, and early morning TV shows he held it before him in the same manner.

Experimentally Izuku gave it a swing. It made for a green blur through the air.

Izuku made a face.

* * *

 _Analysts for the Future Vol 6 Entry 68_

 _Per to todays encounter with subject tentatively titled the Stranger in the Black Coat a new entry is necessary._

 _The new power (not sure Quirk is a term applicable to this?) seems to consist of a hybrid object that's part sword and part key? Has significant weight to it when swung. Building up strength recommended so it can be held with one hand._

 _In response to curiosity about the more key-like tendencies a bit of testing has revealed that the current focus can open up locked objects with a simple touch and after a bit of trial and error, the object can also create a beam of light like a laser that can also unlock things. Unable to confirm whether it can unlock other things without keyholes. More testing is needed._

* * *

The next day the, start of the weekend had Izuku walking through the streets on his way to the nearby woods to test out his new… thing?

As he passed by a park he used to love to go to he heard a cry of pain and to his unhappiness familiar laughter and voices making him stop dead.

 _Kacchan_ he thinks.

Bakugou Katsuki his childhood friend and bully with two of his current companions though lackeys might be more of an apt term had found a new victim.

Izuku looked towards the park not sure what to do.

Fwish!

Izuku looked down in surprise at the object which had just appeared in his hand pulling it down.

Looking down at the object the sunlight gleamed off the eye-like gem in the handguard and it almost seemed like it was looking at him somehow.

 _But what can I do?_ Izuku silently implored as he looked down at it.

Nothing really replied but as Izuku and the gem stared at each other, other thoughts and visions came to mind. Of heroes risking danger for life and limb, of saving civilians, and most of all, All Might came to mind. Of how he would save everyone with a smile no matter what. One of the greatest heroes the world had ever known.

"Do not fear, for I am here…" Izuku muttered All Might's famous slogan to himself.

The young man swallowed and looked towards the park and taking the object with both of his hands he ran.

Running into the park he could see Kacchan and two other boys one whose Quirk had long fingers and the other based around his wings. Another boy smaller than all of them was curled up in front of them.

Acting on sheer instinct Izuku ran for the fingers guy first and with a swing to the shoulder (he didn't want to brain him after all) he was down and the sound caught the boy with wings attention but Izuku was already on him and with two swings he went down and now he had Bakugou's attention.

Pointing the object down to the ground Izuku fearfully stared Bakugou down.

The blonde boy with red eyes looked at him incredulously. "What the hell shitty Deku? You think a toy can really make you a hero?"

Deku, that was Bakugou's nickname for him meant as a slur because his name could be read as useless and had been so ever since his Quirk failed to manifest.

But that was then, this was now.

Izuku swallowed and said "I'm not gonna let you do this Kacchan, it's cruel."

Bakugou smacked a fist against the palm of his hand and sparks swirled around it as his Quirk the ability to make explosions from his sweat activated.

Izuku took a breath.

It was Bakugou who made the first move fists a-swinging and Izuku out of sheer instinct raised his weapon up placing his other hand on the shaft of the blade(?) and raised it before him as if to shield himself with it.

And that is precisely what happened. As Bakugou's hands flew in the air over the weapon they struck something invisible and he was repelled back by the force.

The two sort of just stared at what happened incredulously for a moment before Izuku sort of snapped out of it and brought both hands to the handguard and swung at Bakugou but the hit shook Bakugou out of his stupor and he immediately punched back and one wild swing knocked his weapon out of Izuku's hands.

And a punch sent Izuku to the side and Bakugou proceeded to step between Izuku and the object.

"Not so tough without your toy are you Deku?" Bakugou sneered.

Izuku reached his hand forward as if to reach for it and…

FWISH!

It was back in his hand weighing it down much to both of their astonishment, again!

Izuku immediately swung again and got in another hit sending Bakugou stumbling back and again Bakugou shook his surprise off and tried to swing again and Izuku awkwardly raised his weapon up at an angle so the flat of it was between them like a shield.

He wasn't really expecting it to do any good but again as Bakugou tried to swing past it and again his fist struck empty air repelling him back again and again Izuku took the initiate as he swung again and he watched astonished as Kacchan went down and stayed down.

He just stood there breathing hard for a moment and **then** he remembered the kid Kacchan and the other two had been picking on and he whirled around to see them staring at him incredulously.

Hearing Bakugou and the others start groaning Izuku dashed forward weapon in one hand and with the other hand he pulls the other boy up and along and the two are running.

They get a block away and then Izuku looks at the other boy and says "go!" The other boy looks at him in awe saying "thank you" before running off.

Izuku sighs and then jumps hearing Bakugou scream "DEKKUUUU!"

FWOOSH!

Izuku looked down to see a scorch mark at his feet. As for where it came from? Well much to Izuku's wide eyes the answer to that no doubt lay in the flames that flickered at the edge of his weapon.

* * *

 _Entry 68 Continued_

 _While I have not yet tested this weapon's unlocking abilities recent developments have revealed some surprising things some of which I cannot label or explain really._

 _1\. If knocked from my hands I can resummon the weapon to my hand wherever it is. If there's a range I don't know. Testing may be required._

 _2\. The weapon can apparently use some sort of shielding ability._

 _3\. Even more concerning this thing can also apparently shoot fire-based projectiles which is something._

 _Again, more testing is needed. A notebook dedicated solely to this new power is probably a good idea._

* * *

The next day found Izuku in the woods by a certain creek where a certain incident once happened.

He was staring down at the waters of the creek and he looked very apprehensive. Reaching out with one hand he summoned the strange object he'd been given once more.

He examined it.

No flames.

Taking it with both hands he experimentally swung it then examined it again.

Still no fire.

Izuku frowned. _Maybe I have to focus?_ He thinks and he focused on flames and sure enough flames appearing at the end and he flicked the weapon slightly and the flames leapt off the edge in the form of a projectile that knocked him back a bit from the recoil but he wasn't really minding that as much as he was minding the fireball that went up and swerved down into the river going out with a fwoosh letting some steam rise into the air.

After just observing the steam vanish for a seconds Izuku took a breath. Raising the weapon once more he braced himself and concentrated and sure enough another fireball flew into the river with a fwoosh.

As steam rose into the air Izuku thought to himself _OK so concentration is the key here, now for target practice._

He fired off another projectile with a bit of a pant observing the way it fell.

Observing the spot where it fell in the water Izuku frowned and pointed again to fire another projectile… and nothing happened.

He blinked and looked down at the mysterious object. Something about the eye almost seemed to be saying, what?

He tried again and nothing happened.

Focusing again Izuku tried again and again he could feel something and then there was flames flickering at the end of the weapon and they went away as Izuku felt his knees buckle and the grass rushing up to meet as he passed out in the sunlight.

* * *

Green eyes slowly blinked open and Izuku looked at the forest from the shade of a tree. He just took in the scene for a moment and then eyes roamed down and saw the mysterious object he had been given recently and then it came back to him what he had been doing and more importantly he did not pass out in shade comfortably like this!

Getting up and looking to his side he came to look up a familiar (so to speak) figure in a black coat lounging against the base of a tree and jumped back with a yelp making the man look at him.

"Oh, you're up." He said as he closed his book with a snap attracting Izuku's attention for a moment.

The book was bound in a fine black material and pressed into it was the silver shape of a winged heart emblem but that was irrelevant particularly since he managed to make it vanish somehow in the next moment as he said "you know you should really be careful, you're just starting out and it'll take time to build up your magic and exhausting yourself like that is no good."

Izuku's eyes widened and he gaped for a moment before he got to his feet and exclaimed "that's magic?! Magic is real?!"

"Yup." The man simply replied as he too got up and said "it's just one of the handy-dandy benefits that comes of wielding a Keyblade."

That particular word immediately caught his attention "Keyblade?" He asked.

The other man nodded "yup that's what the weapon you now wield is called. And those who have them are called Keybearers." He raised one hand palm up as light gathered above it and formed the shapes of Keyblades above it. "Keybearers are brilliant warriors whose hearts shine with light and fight back evil and have the power to bring happiness, change, destruction, salvation, sorrow and so many other things" he explained to an awestruck Izuku.

"Oh, by the way that particular Keyblade I gave you doesn't have a name, so feel free to name it yourself. Also, you can call me the Master of Masters not the Stranger in the Black Coat."

Izuku squeaked as he thought _how did he, did he read my notebooks?_ But that thought fell to the wayside when something occurred to him and he asked "hey Master?"

"Hmm." He said.

"Why?"

"Why what?"

"Why… why would you give this Keyblade, this power to me?"

The Master of Masters titled his head to the side and said "you really want to know."

Izuku nodded and implored him "yes!"

His response was blunt "I wanted to see what would happen."

Izuku face planted into the dirt.

"Oof" the Master said "that looks like it hurt, if you're gonna make this a habit. I may as well give you the Cure spell now careful though it uses a lot of magic." He waved his hand and Izuku's body glowed with light as he felt something course through his body and right after that Izuku sprang up clawing the air in front of him as he tried to formulate some sort of response to everything he was doing, everything he had done but words failed him as he did have an answer flippant thought it may be as his arms dropped limply to his sides and he stared at the ground as he said "what am I supposed to do now?"

He wasn't expecting a response really but he did get one "may your heart be your guiding key."

"Huh?" Izuku said looking up at the Master who had a hand over his heart.

"It's a phrase I say all the time and it's something Keyblade wielders say to each other. Ultimately what you need to do is what your heart feels is right."

At these words as Izuku looked up at him he felt tears well in his eyes and the Master shook his head saying "no no no, no tears, sadness is bad for Keybearers though…" He gave Izuku a considering look "I guess with you it can't really be helped and friends… Might be a bit of an issue with you for a while." He raised a hand to where his chin would be and made a tapping motion as he considered before he snapped his fingers and said "I know!"

He reached out to Izuku and plucked a hair off his head and his other hand was suddenly holding a glass flask in his hand and in the round chamber at the bottom was something glowing that changed colors. Bringing the hand holding the hair over to the rim he dropped it in and the hair was engulfed by the mystery substance and the Master of Masters made a finger flexing motion at it as if flashed white and rose up and out of the flask and as it left the flask it grew into a sphere that was about half Izuku's current height and when it hit the ground the light faded and Izuku stared wide eyed at the creature that was now before him.

It was a little gray and white cat standing on two legs. It had blue eyes, a white collared cape, and pink coin purse with a white star on it. The thing looked rather like a plushie and yet he could hear it breathing.

"Hi there!" It said in a soft voice as it waved.

Izuku started "what, who are you?" He amended.

The Master of Masters said "this is Chirithy, he's a Spirit, a creature not unlike a cat or dog and he'll be your loyal pet and friend."

Chirithy hopped forward making noises as he did so and Izuku picked him and hugged him close as Chirithy giggled not noticing the way his white cape fluttered up revealing a strange pink symbol on his back.

Izuku buried his face in the fur of Chirithy's head and as the little cat pawed him and then Izuku raised his head to thank the Master but stared at empty air.

He was gone and then the light dawned as it occurred to him that he had to bring Chirithy home with him and oh God, Mom!

Cue the panic again.

* * *

Midoriya Inko closed the door to her son's room where her precious baby now lay in bed sleeping with his new friend? Pet? Strange creature that an even stranger man had given him and did who knows what else to him.

Fretting the woman walked over the phone and picked it up intent on calling someone.

"Hello Mrs. Midoriya, that won't be necessary."

The woman eeked, dropped the phone, and spun around.

The Master of Masters was sitting at the kitchen table waving at her with one hand and his other… was holding the phone she had just dropped.

She looked down and sure enough the phone wasn't on the floor.

She leveled a glare at the man then glanced between her son's room and the front door as if considering the best way to run out of here.

The Master said "again that's not necessary Mrs. Midoriya."

The woman scowled at him and before she could say anything the man said in flat, dead tone "if I wanted to do something bad to you and your son, it would have happened already and I think it's clear that neither of you can really stop me if I did want that. But did I? No, I didn't. Instead I've looked after your son when he injured, when he was unconscious, and I've granted your son the power to defend himself, to chase his dreams, to be a hero. I am no threat to you really so none of that's necessary."

He looked at the taken aback woman who was shaken by those valid statements and then he went for the metaphorical jugular as he said "besides what are you gonna tell people, it's magic."

Inko fell over at this statement.

The Master just watched this dully as he said "huh. So that's where he gets it from."

The woman weakly picked herself up off the floor as she said "what am I supposed to do now?"

He tilted his head and said "what I said to Izuku earlier today, may your heart be your guiding key."

The woman stared at this strange person and recalled the definition of the phrase of Izuku had given her earlier when he come home with Chirithy.

But before she could say anything else the Master shrugged and said "welp, I've said my piece can't do anything else. What happens next is your own choice." Then his form flashed with light and when the glow faded he was gone leaving Inko to stare at the space where he had been in bewilderment.

Then she ran back to her son's room and confirmed that Izuku and Chirithy were still asleep in there and looked to the phone again.

She honestly didn't know what to do. Ideally, she should call the police and get the heroes to help her and her son with this but at the same time the "Master of Masters" had a point he had done them no harm when he was clearly capable of it and even more had done more of her son and his dreams than she had been able to in years.

Did that mean she trusted the man? Hell no!

But… she looked at her son who was cuddling with the strange little cat he brought home and sighed. But for the sake of her son and his dreams and that he could finally defend himself she could accept this even if she was not okay with it really but Izuku needed this, and more importantly she could see that he wanted this.

So yes, she would accept this but she would not trust the man and she would certainly keep a watchful eye on Chirithy and this "Master of Masters" but she would support Izuku and do all that she can.

Again, it was all she could do really.

* * *

 **Author's Note: Hello everyone! Here's the newest chapter of my new Boku no Hero Academia fic! I'll be honest I wasn't sure what I was expecting when I posted the prologue but I got a good chunk of positive feedback and it meant the world to me thank you much everyone. So I hope you like the chapter. To address 3 points here the first being how the fight with Bakugou went I'm a little worried about the flow of it so if you want to give feedback on that I wouldn't say no. As for why it was so short we are talking about kids brawling in a playground arguably it's not gonna last very long. Point two Izuku got the block ability pre-programmed into the Keyblade and the fire spell was gained with his slight triumph over Bakugou gaining abilities and such like this and through other experiences will be a theme somewhat so heads up. Point three is the ending. I really wouldn't mind feedback on this because I was trying to address the logical view behind such a situation but I was also trying not to push too hard on it because of how awkward that could be so feel free to give feedback on that too. Not much else to say really. There's a picture that goes along with this that I drew and will be up on the other sites I use so feel free to check that out. Big thank you to my friend and beta reader Tolby for helping me with this. I don't own Boku No Hero Academia or the Kingdom Hearts series in any way, shape, or form. Reviews welcome!**


	3. Chapter 02

The Key That Connects All

Chapter 02

Things Old and New

"So high school is approaching and all of you need to begin thinking about the future… but let's be real everyone's probably aiming for the hero course!"

And papers were flung into the air as quirks of sorts went active in the classroom.

Izuku head in hand just observed the chaos idly as this happened.

In the past 6 years, quite a few things had changed for the quirkless young man, he looked… steadier and if one cared to really look they would see lean muscle underneath the junior high school uniform. Where in another time and place Izuku might show more signs of being hurt and bullied. This world not so much, quite a lot has changed…

"Hey teach don't lump me in with all these extras!"

But on the other hand, some things have stayed the same.

The blonde with the explosive quirk stood on top of his desk and with a jerk of his thumb to his chest Bakugou proclaimed that only he stood a chance at getting into UA and that everyone else were just extras. As the rest of the class shouted protests Izuku rolled his eyes. Then disaster struck.

"Oh right, wasn't Midoriya looking to get into US as well?"

And then the rest of the class turned to him while he closed in eyes a mixture of mortification and… annoyance.

"Midoriya, get into UA? Yeah right!"

"Seriously, he doesn't have a chance."

"He doesn't even have a quirk!"

Then hands slammed down onto his desk sparks crackling around them as a livid Bakugou glared down.

"You looking down at me you worthless Deku?!"

But before anything else could anything the teacher called out "Bakugou! That's enough return to your seat!"

The blonde bomber did so though his eyes promised a message that clearly said this isn't over.

And Izuku let out a breath as he did so knowing that, that whole thing was going to be a pain to deal with.

The school day went on like normal and as the day ended and the bell rang Izuku was ready to go but Bakugou was too and so were his cronies but Izuku merely looked past them as he narrowed his eyes on a particular spot trying to focus.

"Thunder…" He breathed out and there were several gasps as a bolt of lightning emerged from the ether in the back of the classroom and struck the tiling creating quite the display.

Then with everyone distracted Izuku made a run for it. And it's not like anyone would think he had anything to do with it.

Afterall he was "quirkless" so what about his keyblade and his magic, what could he tell people it's magic!

As for when Izuku gained that thunder spell, well that had happened sometime over the past few years and that wasn't the only trick he had picked up too…

He bounded past the other students and behind him he suddenly heard Bakugou screaming.

"DEKU!"

That was incentive for him to move faster and beelining it for the courtyard he circled round back to an alleyway formed by a storage shed and a wall.

After looking to make sure no one in sight he with his right foot he braved it on the wall and fueled by intent and the started by that motion his whole form alighted with green light and pushing off he sort of soared up the wall and guided by the power surrounding him flipped over the wall and landed on the pavement on the other side.

As the energy faded Izuku quickly looked around to make sure no one had seen him.

They hadn't.

So, with Bakugou yelling indignantly in the distance Izuku took off.

Sometime later Izuku arrived at his destination in question: Dagobeh Beach. Once a seaside nature park, now by chance, nature, and people a trash dump.

And it was Izuku's training ground.

For the past year Izuku had been cleaning out the trash as something of a new training regime. Part of him was just carrying trash, the other part?

After checking again to make sure no one was around Izuku raised up his arm as if to grab something and there was a fwish sound as his keyblade or Heroic Gaze as he now called it came into his hand.

Notably the weapon's weight was still the same as it had been when he was first given it. But with the passing of years Izuku had put on some muscle and could handle the keyblade with relative ease.

Hefting the weapon Izuku looked towards the remains of what looked like a car wreck. Then there was a puffing noise followed by a soft thump, looking behind him he smiled at Chirithy who was now standing there.

"Gonna try and get the car done today Izuku?"

Izuku nodded saying "yup. Wanna get some Shotlock practice done today."

Chirithy nodded and said "well your skill with Shotlocks is getting better and better."

The human smiled before turning back to the car.

Over the past few years Chirithy had been a good friend to him. Supportive, steady, and empathetic and even more than that Chirithy knew quite a lot about the keyblade. The little being had been a huge in his development but there was a drawback.

Chirithy for some odd reason could only really tell him about abilities and such until after he had discovered them.

Holding Heroic Gaze firmly Izuku narrowed his eyes and cast them about, scanning, imagining, focusing his intent then he felt power gather along the end of his keyblade and with a flick sent it flying.

"It" being a small series of green bolts of electricity that arced through the air before converging on the car.

There was a series of crackling, cracking, rattling, and breaking noises.

When it all stopped parts of the car got broken off but the thing was still standing there.

Izuku let out a huff. _I really thought more of the car would be gone after that._ He thought.

"Don't be too hard on yourself Izuku! Shotlocks come in all shapes and sizes and there's a sort of set limit to using them. You're getting better and better."

Izuku looked at Chirithy, nodded and smiled.

It had only been a bit at the beach but Izuku was already heading home. School day means only so much training, Mom gets anxious waiting for him.

Though considering the time's he's overexerted himself and passed out maybe it was warranted.

Izuku sighed at the thought as he walked under a bridge and then stopped dead hearing a strange noise and a voice behind him.

"Oho what's this a medium sized invisibility cloak?"

Izuku turned around and that was a lot of slime heading for him.

Being light on his feet Izuku jumped backwards as Heroic Gaze came into his hand and the slime man observed him curiously.

"Oho… That's a peculiar quirk you've got there."

 _OK yeah, this guy's definitely a villain_ Izuku thinks not liking the look of him now at all, not that he ever did but such musings were cut off as the villain lunged for him and Izuku responded by dodge rolling out of the way.

Finishing said dodge Izuku aimed his keyblade at the villain and called out "freeze!" Firing a bolt of ice at him.

Which froze a small piece of him not really doing much but it did get him to scream for some odd reason.

As he finished the scream the villain refocused on him, body shifting, eyes alight with fury as he roared "why you little!" And that was a ridiculously long and big arm heading for him.

A dodge roll under that and there was the second and Izuku immediately spun Heroic Gaze in his grip bringing the end his weapon to his other hand and his blocking ability went active a sparkling barrier appeared and the fist coming for him was struck back the villain crying "what" as it did so.

And with immediate if shaky movement from the nerves and adrenalin the end swung back at the villain and said "thunder" and a bolt of lightning struck true and the villain screamed in pain.

In the back of Izuku's head the analytical part of him noticed parts of the villain were retracting back into himself.

But all too quickly the moment faded and the villain now very much incensed tried a new tactic.

Sending parts of his body out he tried to encircle Izuku. Time almost seemed to slow down again and Izuku was quickly panicking as he tried to strategize. Blizzard, fire, aero, or thunder wouldn't work very well here.

Shotlocks weren't a good idea either.

So that meant trying something new.

Quickly raising his keyblade skyward Izuku tried for a spell he had only really ever done in brief flickers before: reflect.

Channeling magic into his keyblade and praying to all the powers that be that this works Izuku loudly called out "repel!"

And with the vision of what he wanted in mind a sparkling barrier surrounded him like a crystalline sphere. One the villain couldn't get through though he was trying as he did Izuku felt a HUGE strain on his magic and while he had fairly built it up over the years this was not sustainable at all.

And if he needed to use a cure spell…

Nope. This needed to end now.

Quickly looking around again Izuku noticed out of the corner of his eye a wall located oh so conveniently behind him and in that moment, he felt his nerves settle somewhat as the beginning of a plan started to form.

With no real time to plot anything else Izuku proceeded to go for it timing it just so Izuku dropped the barrier and jumped for the wall and once more as his foot his the pavement his body lit up with green light but instead of the smooth motion from before like a magnet snapping into place Izuku coiled down in a crouch that was perpendicular to the wall and his head went up to look at the villain, eyes narrowing.

His mind moving at high speed he outlined what little he knew about the enemy before him based on everything he had done and said before and during their fight before they settled on his eyes and mouth, figuring that was where it would be optimal to strike.

Letting loose with the power surrounding him, the ability called Flow Izuku flew right for the enemy and reared back and struck the ground with his weapon releasing a shockwave attack. As slime flew out and the villain reared back from the point of impact Izuku decided to follow up with one of the more powerful tricks he had picked up recently.

Pointing Heroic Gaze right at the slimes face and let loose with Fira at point blank range.

There was a scream from the villain and he was starting to look haggard but still rearing to go but then there was the sound of police sirens in the distance making them both stiffen.

Then before Izuku could do anything else the slime villain decided to make a run for it, heading for the manhole cover and was gone leaving the keybearer just staring there tired as heck.

After a few seconds and nothing else happened Izuku sagged down into a crouch using Heroic Gaze as a makeshift crutch and then there a puffing noise as Chirithy appeared.

"Are you okay Izuku?! That fight looked really nasty."

Laughing a bit at his dirty and ruffled uniform but still his focus was: "careful Chirithy that villain might still be around."

Chirithy just shook his head though saying "I don't sense him anymore."

Deciding to hand wave that while putting it in the "notes to put in the Chirithy Analysis Journal" (which said cat has doodled and decorated in) for later he said "Chirithy."

"Yeah?"

"Find a payphone please? We need to report that villain."

"Sure! Anything else?"

"…remind me when get home to plan for more endurance training."

"OK." The little cat replied simply.

One phone call later and Izuku was wandering through the streets of Musutafu heading home. He had sent Chirithy ahead so his Mom wouldn't worry.

There were still traces of slime on his uniform and while Izuku still looked rough but he was OK-ish.

However, as he made his way home, he noticed a crowd of people scattered about and… were those buildings on fire?!

Approaching the incident wondering if a hero fight was taking place Izuku heard whispers of conversation.

"…a villain…"

"…heroes can't do anything…"

"…fires…"

"…hopefully he can hold out…"

The situation didn't sound good to Izuku and so curious, he craned his head trying to get a look but was only able a glimpse but the one glimpse made his blood go cold.

He saw two things that very familiar for very different reasons.

The first was slime that he still had some traces of on him.

The second was a very familiar red eye he'd know anywhere and despite… everything a part of his heart clenched at the vision.

 _Kacchan!_

And so, throwing God knows only how many things out the window, moving without thinking Izuku headed for the nearest wall in something of a dash calling upon Flow and jumping into the air he saw the sight that despite himself he didn't want to see.

In the next moment Heroic Gaze was in his hand and pointing it at the scene below he focused on what he wanted and as he did so he felt his keyblade gather power in a new way… a new Shotlock.

 _May your heart be your guiding key._

With a breath Izuku let it go.

* * *

 **Author's Note: Hello everyone surprise! Here's the new chapter. Thanks to everyone for all the support! Sorry it took me so long. For those new to my stuff and the way I operate I basically rotate the fics I work on with random projects coming and going in addition to school and other stuff that takes place IRL. It takes me forever but I do get stuff done so here it is. Not really sure what to say here beyond that I worry about how the fight scene went though Tolby says it went fine. I'm also worried a bit about how the abilities worked out but here we go. If you have advice/suggestions on that I'm willing to listen. For those wondering Kingdom Hearts 3 didn't have a big impact on this so that's a thing. There's a drawing to go with this that's up on AO3, DA, and Pillowfort. A big thank you to my friend and beta reader Tolby for helping me with this. I don't own Boku No Hero Academia or the Kingdom Hearts series in any way, shape, or form. Reviews welcome!**


	4. Chapter 03

The Key That Connects All

Chapter 03

Things Come to Light

To all those watching the scene things then took a very sudden and confusing turn as 7 green translucent, hexagonal panels appeared in a ring around the villain with the seventh appearing right above them and then there was a green blur charging with electricity zoomed in to the villain, checking the sludge monster as it came to a stop on the first panel and then going diagonally the blur charged for another panel again slamming the into villain agitating him and making him loosen his grip on Bakugou ever so slightly.

This attack repeated 4 times and on the final one the blur went for the middle panel and hit it, reversed inertia and pushing downwards he slammed into the ground letting loose a huge shockwave that blew the villain back and let Bakugou go free.

Bakugou, who just stared at what happened with a rather blank face for two reasons, the first?

During that whole assault while Bakugou had certainly gotten jostled and affected by the movement of things. He unlike the villain didn't take damage from the energy and raw power that the villain had certainly seemed to take. Even though it seems like he should have, he was certainly close enough!

Point two, the mysterious interloper/attacker was gone even though after that impact he should be in plain view!

But before these things could really be addressed the heroes who at this point had been standing nearby uselessly (with the exception of Kamui Woods who was helping civilians) moved into action.

And in all the chaos no one noticed Izuku drop down onto the pavement from thin air or rather the point in the air where he had channeled and fired his shotlock.

He crouched down on the pavement and gasped both from the feeling of adrenaline and the loss of the wellspring of power he draws shotlocks from completely spent.

There was a puffing noise that went unheard by all but Izuku and then Chirithy landed on the pavement and looked up worriedly at his friend.

"Izuku are you alright?"

"I-I'm fine Chirithy. Just tired."

The little cat nodded and looked at the chaos and then back to him saying "we should go. Quickly and quietly."

Izuku looked uncertain and weakly protested "but…" He trailed off.

Chirithy had a point.

Technically he should not have interfered and confessing also means having to answer questions he had no real answer for.

Or at least one's people could easily believe.

So, he nodded and scooped up Chirithy who wiggled in his grip, his protests the weak ones this time around as the duo made their getaway successfully.

And… the chaos also hid the laments of someone else.

Someone who looked on with an emaciated body who wishes he could have helped. That he could do something. But he can't he's powerless to do much of anything anymore…

He's failed. In all the ways that count…

* * *

Meanwhile as Izuku walks through the streets holding Chirithy who by now.

The two were enjoying the ending of a now-quiet afternoon.

Which of course means something has to happen as destiny now took yet another new turn and rounding the corner Izuku walked straight into someone and the two tumbled downward one of them actually squawking as they did so!

And when their perspective settled Izuku found himself on his side staring at a boy who had a bird head with black feathers, yellow beak, and red eyes.

Said boy was dressed rather simply and was also staring back at him rather bewildered.

There was about a beat of silence for one second, two. Then Izuku screeched as he leapt up and went into mumbling mode dropping Chirithy as he did so.

"OhmygoshIamsosorryIamsuchaklutzIwasn'tpayingattentionohgeezareyouokayIamsucha…" and he went on like that as he pulled the other, rather confused teen up.

Though after a moment he raised a hand palm up the classic halt gesture as he said "stop. I am fine. It is OK."

Izuku gaped like a fish unsure what to say and the other teen went silent too before awkwardly he cleared his throat and said "Tokoyami."

"Huh?"

"My name. It's Tokoyami, Tokoyami Fumikage."

"Oh! Uh Midoriya Izuku."

The other teen, Tokoyami, nodded and then looked down and said "and this is?..." As he gestured at Chirithy who gave a start as he realized he was still here which was odd as he did not like to be out around people that weren't Izuku or his mom but apparently, he kinda been too stunned to vanish.

So now they had to deal.

Izuku gaped like a fish again as he went "uh… this is my cat Chirithy."

Tokoyami looked at the plushie-like creature shrugged and before anything else could happen a strange voice spoke up.

"KITTY!"

And there was a blur of purple and Chirithy was wiggling in the grip of something purple-black and vaguely bird shaped with glowing yellow eyes?

It nuzzled Chirthy with its head going "Chiri-kitty! Chiri-kitty!"

And Chirithy was wiggling in its grip before crying out "Izuku help!"

And that finally snapped Izuku out of his stupor but before he could act.

"Dark Shadow!"

The other boy moved and berated the other creature and then Izuku noticed that the creature had a cord of some kind connecting it to Tokoyami.

And as Izuku took all this in he watched as Tokoyami successfully extracted Chirithy from Dark Shadow(?) and turned to Izuku "my apologies Midoriya my quirk can be a bit much sometimes" and here the entity was at his shoulder whining about "all I wanted was to pet the kitty" and "you never let me have any fun Fumi!"

Izuku quickly scooped up Chirithy and hugged him close as he said "It's okay Tokoyami. Um your quirk… it's sentient right? That's pretty rare."

The bird boy nodded "correct and rare though it may be Dark Shadow can be… a handful at times. Your cat… they have a quirk too and are sentient?"

Izuku nodded a little awkwardly.

Tokoyami looked away and then back to Izuku "I should take my leave now before the winds of fate or Dark Shadow (at this came an indignant "hey"!") cause something calamitous to happen. It was a pleasure to meet you both. Maybe we shall meet again one day."

And quickly the other boy trotted away somehow managing to keep Dark Shadow on a leash though that might have been more literal than he meant it too and then Midoriya remembered his manners somewhat as he said "later Tokoyami," and then before his brain caught up his mouth again he added on "may your heart be your guiding key."

Then he slapped his hand over his mouth mentally kicking himself as the the teen stopped, half-turned to eye Izuku, nodded, and walked away.

Once he was out of sight Izuku let out a sigh and looked down at Chirithy. "I am SO sorry about all of THAT Chirithy. Are you okay?"

The little cat looked up at him and nodded "I'm OK. Those two sure weren't peculiar weren't they. Those two… their whole beings are cloaked in shadow and yet their hearts… they radiate such a warm and strong light."

Izuku looked a little ponderously at that and then "wait hearts? Like more than one?"

Chirithy nodded "yup. His quirk had a heart too."

Izuku blinked "huh."

And then his friend said "we should be getting home Mom worries when we're out like this for so long. And with the big day on the horizon we don't want to put any more stress on her than necessary."

Izuku nodded and adjusting his arms so Chirithy was cradled by his left arm he raised up his right arm and the two watched as soft emerald green light gathered into his hand before expanding outward with a fwish as Heroic Gaze appeared in his grip.

"There's only so much more time before the UA Entrance Exam right?"

Izuku hefted the weapon in his grip and pointed it towards the sky.

* * *

Bakugou Katsuki stalked his way home, dirty and rumpled, smelling of sewage, red in the face feeling angry beyond belief and humiliated beyond description.

He couldn't do anything against the slime villain.

He had to be rescued by some damn interloper who just vanished!

Bakugou was pissed and it was about to get worse as in the distance he spotted Deku.

The nerd was holding some stupid stuffed animal and just as he was about to proceed to grind the trash under his heel he watched as Deku held his arm out and green light that looked **suspiciously familiar** gather in his hand before expanding outward into some weird object.

And then things clicked.

Deku's vanishing acts.

His strength despite being quirkless.

The strange happenings at random or not-so random times.

And then finally this: his rescue by some unwanted interloper.

As all this came crashing down onto Bakugou's head clicking into place an ugly snarl found its way onto his face and one thought was dominant in his mind.

 _SHITTY DEKU!_

* * *

 **Author's Note: Surprise everyone! Here's a new chapter for my BNHA Keybearer AU fic! It took me a bit to manage this but I did it. It's a little short but the plans for my fic had me just doing the basic aftermath so that's what I did. But then looking over said plans I realized I could do something else. The meetcute! Midoriya and Tokoyami have met so that's the first step taken. I'm a little worried about my portrayal of Bakugou but I think this works. So all together that is chapter three. Sorry for the wait everyone. There's a drawing that you can see to go with this up on the other sites I use. A big thank you to my friend and beta reader Tolby for helping me with this. I don't own Boku No Hero Academia or the Kingdom Hearts series in any way, shape, or form. Reviews welcome!**


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